It has been posited that adhering of a polyamide layer to a cellulosic substrate will improve the functionality of the cellulosic substrate, e.g., improve the filtration efficiency of cellulosic filter media or strengthen a cellulosic substrate.
One method that may be considered for adhering the polyamide layer to the cellulosic substrate is by bonding the two together by use of an adhesive therebetween, i.e., a different substance therebetween that effects the adherence.
This method is unuseful for filtration functionality and involves an extraneous substance for all functionalities.
While solvent welding is known to bond soluble plastic to unlike porous surface, including wood and paper, through impregnation and encapsulation of fibers of the unlike porous surface, a problem is presented on how to effect this kind of bonding or variation thereof between a polyamide fiber layer and a cellulosic substrate layer in an operative manner and so that two layers cannot be separated by manually applied peeling forces.